cooling issues..., fine when driving, spikes when stopped. |
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cooling issues..., fine when driving, spikes when stopped. |
malaga_red75 |
Aug 6 2010, 05:52 PM
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#1
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'74 2.5L N/A Subie Group: Members Posts: 454 Joined: 5-March 06 From: Menlo Park, CA Member No.: 5,674 Region Association: None |
subaru JDM EJ25 DOHC
So, got my conversion finally road worthy and have noticed that while I am driving around, the car stays at around 200 F. when i stop, or let it idle in my garage... the temp slowly climbs and doesnt stop (i shut it off around 230 F). I am assuming this is an issue with my fans. I am running a front mounted radiator, using 2 push-style fans. A few things that i think may be wrong... -There is no shroud around the fans... just the shroud that seals the radiator to the front (since they are push fans, they are mounted on the front side of the radiator, in between the radiator and the nose of the car) - there is about a 1 1/2" gap between the fans and the radiator (this was just the way that ended up working for mounting the fans) anyways, i am pretty sure that the cooling system is working (no kinked lines, thermostat working, fans do turn on) as indicated by driving and the temp staying cool, there is just something not working when i stop moving. let me know what you guys think. -Peter |
Mike Bellis |
Aug 6 2010, 07:03 PM
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#2
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Resident Electrician Group: Members Posts: 8,346 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
First, you should pull the air not push. Second, i bet you have small pockets of air in your system. I would recommend you seal the system and pull a vacuum at the high point. This will force all the air to the vacuum.
When I do mine, I clamp off overflow tube on the expansion tank near the engine. Pull vacuum on the front for a few minutes. Take the overflow tube in the engine bay and put it in a bottle of water. Un-clamp the tube and the water will displace the air. Do this several times and all the air will be gone. Mine runs at 150-160 on the freeway, 180-190 stoped. |
ArtechnikA |
Aug 6 2010, 08:07 PM
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#3
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rich herzog Group: Members Posts: 7,390 Joined: 4-April 03 From: Salted Roads, PA Member No.: 513 Region Association: None |
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Mike Bellis |
Aug 6 2010, 11:05 PM
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#4
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Resident Electrician Group: Members Posts: 8,346 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
First, you should pull the air not push. Reference, please - 'cause everybody else in the world says it's easier to push a fluid than suck it... Air from any fan modulates. It may feel like just air blowing but as the blade cuts through the air, the air modulates. When you try to force air into a radiator, the surface design of the radiator will reflect the forced air molecules back on itself. This causes turbulence even before any air gets through the radiator. This action reduces the efficiency of the fan. Fans react more to output turbulance than input turbulance. The energy is the motion of air molecules moving in space. If I pull air from the back side of the radiator, there is no more turbulance than if I run the fan in free air. The efficiency of the fan increases. Air will be pulled through the radiator at a greater rate than if I try to push it. Have you ever tried to push a rope? |
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